Demography of Sex Differences in Health and Survival. Is it true that males are healthier than females but die younger? If so, why? We plan demographic analyses to address these two overarching questions concerning the health-survival paradox. First, to what extent is the paradox true? How general is it? According to which definitions and measures and along which dimensions are men healthier than women? How do male-female morbidity and mortality differences vary with age? How do they vary over place? How have they varied over time? How do they vary across species of primates, other mammals and birds? Second, to the extent that the paradox is true, why is this the case? Various social and biological hypotheses will be tested by analyzing: Human and nonhuman lifetables for males vs. females (Project 1); Data on causes of death for human males vs. females (Projects 1 and 2); Age at death of about 15,000 skeletons of adult males and females from the Mesolithic to about 1600 A.D. (Project 1) Survey and registry data on humans in Denmark, Utah, Russia and China (Project 2), and Detailed longitudinal observations of baboons in the wild in Kenya (Project 3). Strong cross-links between Projects, including shared postdocs, joint Working Groups, and coordinated Specific Aims, will facilitate new interdisciplinary insights. The combination of (1) high-quality human data from Denmark, Utah, Russia and China together with lifetable data on many other populations, (2) an informative animal model (baboons) supplemented with extensive nonhuman lifetable data and (3) sophisticated demographic and statistical analyses will provide a deeper understanding of the basis in adults for sex differences in health and survival and of opportunities to reduce these differences.